Add integration of django-money

- Proper currency support
- Add PurchasePrice field to StockItem model
- This keeps track of both the price and the currency
- Display purchase price on the stockitem detail page

InvenTree/InvenTree/settings.py

@@ -155,6 +155,7 @@ INSTALLED_APPS = [
     'markdownify',                  # Markdown template rendering
     'django_tex',                   # LaTeX output
     'django_admin_shell',           # Python shell for the admin interface
+    'djmoney',                      # django-money integration
 ]
 
 LOGGING = {

InvenTree/stock/forms.py

@@ -124,6 +124,7 @@ class CreateStockItemForm(HelperForm):
         fields = [
             'part',
             'supplier_part',
+            'purchase_price',
             'location',
             'quantity',
             'batch',
@@ -399,6 +400,7 @@ class EditStockItemForm(HelperForm):
             'serial',
             'batch',
             'status',
+            'purchase_price',
             'link',
             'delete_on_deplete',
         ]

InvenTree/stock/models.py

@@ -24,6 +24,8 @@ from markdownx.models import MarkdownxField
 
 from mptt.models import MPTTModel, TreeForeignKey
 
+from djmoney.models.fields import MoneyField
+
 from decimal import Decimal, InvalidOperation
 from datetime import datetime
 from InvenTree import helpers
@@ -135,6 +137,7 @@ class StockItem(MPTTModel):
         infinite: If True this StockItem can never be exhausted
         sales_order: Link to a SalesOrder object (if the StockItem has been assigned to a SalesOrder)
         build_order: Link to a BuildOrder object (if the StockItem has been assigned to a BuildOrder)
+        purchase_price: The unit purchase price for this StockItem - this is the unit price at time of purchase (if this item was purchased from an external supplier)
     """
 
     # A Query filter which will be re-used in multiple places to determine if a StockItem is actually "in stock"
@@ -456,6 +459,15 @@ class StockItem(MPTTModel):
         help_text=_('Stock Item Notes')
     )
 
+    purchase_price = MoneyField(
+        max_digits=19,
+        decimal_places=4,
+        default_currency='USD',
+        null=True,
+        verbose_name=_('Purchase Price'),
+        help_text=_('Single unit purchase price at time of purchase'),
+    )
+
     def clearAllocations(self):
         """
         Clear all order allocations for this StockItem:

InvenTree/stock/templates/stock/item_base.html

@@ -266,6 +266,13 @@ InvenTree | {% trans "Stock Item" %} - {{ item }}
         <td><a href="{% url 'po-detail' item.purchase_order.id %}">{{ item.purchase_order }}</a></td>
     </tr>
     {% endif %}
+    {% if item.purchase_price %}
+    <tr>
+        <td><span class='fas fa-dollar-sign'></span></td>
+        <td>{% trans "Purchase Price" %}</td>
+        <td>{{ item.purchase_price }}</td>
+    </tr>
+    {% endif %}
     {% if item.parent %}
     <tr>
         <td><span class='fas fa-sitemap'></span></td>

requirements.txt

@@ -26,5 +26,6 @@ django-tex==1.1.7               # LaTeX PDF export
 django-weasyprint==1.0.1        # HTML PDF export
 django-debug-toolbar==2.2       # Debug / profiling toolbar
 django-admin-shell==0.1.2       # Python shell for the admin interface
+django-money==1.1               # Django app for currency management
 
 inventree                       # Install the latest version of the InvenTree API python library